Intel graphics

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Revision as of 21:30, 26 August 2012 by City-busz(Talk | contribs)(→‎X freeze/crash with intel driver: Shadow option was removed from the driver, the recommended way is to use the NoAccel option. The semaphores issue with the Sandy Bridge graphics was resolved long time ago.)

Models

It is a popular mistake to think of "Intel 945G" and "Intel GMA 945" as being the same graphics chip with different names. As a matter of fact, the latter does not exist. Intel uses "GMA" to indicate the graphics core, or the GPU. Anything other than that is actually the model of the motherboard chipset, like "915G", "945GM", "G965" or "G45".

The more common GPUs and their corresponding motherboard chipsets are:

GPU Chipset/Northbridge
Intel GMA 900 910, 915
Intel GMA 950 945

The "i810" chipset (again, motherboard; not GPU) is actually really old and was manufactured long before the 9xx product line with which the GMA onboard-graphics branding began. Similarly, alternative names for the 910, 915 and 945 chips may include the i prefix.

Installation

Install the xf86-video-intel package which is available in the official repositories. It allows to preset your desired acceleration method. SNA is the recommended method from now on. Check benchmarks done by Phoronix [1]. These can be found here for Sandy Bridge and here for Ivy Bridge. UXA is still a solid option, if experiencing trouble with SNA. Add this to /etc/X11/xorg.conf or create /etc/X11/xorg.conf.d/20-intel.conf :

Configuration

There is no need for any kind of configuration to get the Xorg running (an xorg.conf is unneeded, but needs to be configured correctly if present).

One thing that you should have already done from the start (not a configuration step per se) is to add your user to the relevant group:

# gpasswd -a username video

KMS (Kernel Mode Setting)

KMS is required in order to run X and a desktop environment such as GNOME, KDE, Xfce, LXDE, etc. KMS is supported by Intel chipsets that use the i915 DRM driver and is enabled by default as of kernel v2.6.32. Versions 2.10 and newer of the xf86-video-intel driver no longer support UMS, making the use of KMS mandatory[2]. KMS is typically initialized after the kernel is bootstrapped. It is possible, however, to enable KMS during bootstrap itself, allowing the entire boot process to run at the native resolution.

Note: When using KMS, you must remove any deprecated references to vga or nomodeset from your boot configuration.

To proceed, add the i915 module to the MODULES line in /etc/mkinitcpio.conf:

MODULES="i915"

Note: If you have a first generation Core i{3,5,7} series processor with an integrated GPU, failure to add i915 to the MODULES array in /etc/mkinitcpio.conf will likely cause the error kernel: intel ips [...]: failed to get i915 symbols, graphics turbo disabled.

Note: You may need to add the intel_agp module too if the system complains at boot time.

Now, regenerate the initramfs:

# mkinitcpio -p linux

and reboot the system. Everything should work now.

Tips and tricks

Setting scaling mode

This can be useful for some full screen applications:

xrandr --output LVDS1 --set PANEL_FITTING param

where param can be:

center: resolution will be kept exactly as defined, no scaling will be made,

full: scale the resolution so it uses the entire screen or

full_aspect: scale the resolution to the maximum possible but keep the aspect ratio.

If it does not work, you can try:

xrandr --output LVDS1 --set "scaling mode" param

where param is one of "Full", "Center" or "Full aspect".

KMS Issue: console is limited to small area

One of the low-resolution video ports may be enabled on boot which is causing the terminal to utilize a small area of the screen. To fix, explicitly disable the port with an i915 module setting with video=SVIDEO-1:d as you kernel command line parameter in your bootloader. See Kernel parameters for more info.

If that does not work, you may also try disabling TV1 or VGA1 instead of SVIDEO-1.

Hardware video acceleration

If you want to enable hardware accelerated video decode/encode in multimedia applications (such as VLC or MPlayer) for Intel HD graphics controllers (Ivybridge, Sandybridge), install the libva-driver-intel package, available in the Official Repositories.

To take advantage of VA-API, use a VAAPI supported video player. If you use mplayer, install mplayer-vaapi, and use -vo vaapi parameter. To enable hardware video decoding in flash, add EnableLinuxHWVideoDecode=1 to /etc/adobe/mms.cfg. If hardware video decoding is still not working, you can also try adding OverrideGPUValidation = 1.

Setting gamma and brightness

Intel offers no way to adjust these at the driver level. Luckily these can be set with xgamma and xrandr.

Gamma can be set with:

xgamma -gamma 1.0

or:

xrandr --output VGA1 --gamma 1.0:1.0:1.0

Brightness can be set with:

xrandr --output VGA1 --brightness 1.0

Troubleshooting

Glxgears shows low performance results

Note: glxgears is not a benchmark tool for performance comparison between multiple systems.

If you run glxgears in order to check your system's graphics performance, you may notice it showing results around 60 FPS. For example: